The present invention relates to doped, pyrogenically prepared oxides, a process for their preparation and their use.
It is known that pyrogenically prepared oxides can be coated with metal salts or metal oxides by mixing the pyrogenically prepared oxides with aqueous solutions of metal salts and then drying and/or calcining.
Products prepared in this way have the disadvantages a) that the doping substance is not homogeneously distributed in the entire primary particle or b) that, depending on the type of doping, inhomogeneities may occur during mixing. Thus, after doping and calcining, the primary particles of the doping substance may separate out and be present with much larger diameters than the primary particles of pyrogenic oxides.
It is therefore an object of the invention to achieve homogeneous doping of pyrogenically prepared oxides with another substance while at the same time avoiding problems of the prior art, and more particularly, to avoid the presence of separate primary particles of the doping substance or oxides of the doping substance alongside primary particles of the pyrogenically prepared oxide.